[lutach]

It all comes down to the amount of AMPs used by the higher voltage of the 6S to get the same power as the 4S.

Example:

1500 (watts)/14.8 (4S)= 101A
1500 (watts)/22.2 (6S)= 67A

You will need to select the right Kv motor and gear both the same and you'll see a much more efficient and cool running set up with higher voltage set up.